How to see the actual commands blender runs
Consult the docs

What you are seeing in this instance is an object property. Blender uses operators as "command" clearly recognizable from bpy.ops. namespace. 

For the case shown::

It has ID object of type screen (bpy.types.Screen) an instance bpy.data.screens["Default"] akacontext.screen  and a property name of texture_context  

This means we can find it from the screen object following chain of collections or pointers screen.foo.bar[0].blah.texture_context where none of foo, bar, blah will be an ID object. It is this chain that can be abbreviated to "...". Without can produce ridiculously wide tooltips. 

(Reminder to self) Before pecking about aimlessly in the python console why not consult the docs.. Using the right click and view docs outlined here will take you directly to the help page.

Searching the old** API manual using just the property name.



we find that texture_context is a member of bpy.types.SpaceProperties as shown in tooltip.  A space belongs to an area, an area belongs to a screen. 

You set the space of an area when selecting the editor type, in this case we want the area of type  'PROPERTIES', aka the Properties editor which has an  active space of type SpaceProperties  (tip can toggle an using area.type = 'PROPERTIES')

Scripting

Here is an example using the py console (bpy.types.SpaceConsole).  

&gt;&gt;&gt; for i, a in enumerate(C.screen.areas):
...     if a.type == 'PROPERTIES':
...         i, a
...         break
...         
(1, bpy.data.screens['Scripting']...Area)
# bpy.data.screens['Scripting'].areas[1]    

&gt;&gt;&gt; a.spaces.active.texture_context
'MATERIAL'

&gt;&gt;&gt; space = a.spaces.active  
&gt;&gt;&gt; space.texture_context = 'WORLD'


If your script is going to be invoked from a button or menu in the properties area, can use.

space = context.space_data
# or 
space = context.area.spaces.active


albeit this may seem convoluted, you'll find blender follows a pretty consistent data structure.

** Note

I believe this property has been removed from 2.80 and searching the new manual will direct you to the API changes page.